1. Field of the Invention
The present invention relates to a solid oxide fuel cell (SOFC), and an assembling method of the same, and particularly to an SOFC having a (flat-plate) stack structure in which sheet bodies and support members are stacked in alternating layers, and an assembling method of the same.
2. Description of the Related Art
Conventionally, a solid oxide fuel cell having the above-mentioned stack structure has been known (refer to, for example, Japanese Patent Application Laid-Open (kokai) No. 2004-342584). In this case, the sheet body (may also be referred to as “single cell”) can be a fired body having a flat plate shape in which a solid electrolyte layer formed from zirconia, a fuel electrode layer, and an air electrode layer are arranged in layers such that the fuel electrode layer is formed on the upper surface of the solid electrolyte layer and such that the air electrode layer is formed on the lower surface of the solid electrolyte layer. For each sheet body, the support member (may also be referred to as a “separator”) adjacent to the upper side of the sheet body is also referred to as an “upper support member”, and the support member adjacent to the lower side of the sheet body is also referred to as a “lower support member”.
For each sheet body, the perimetric portion of the sheet body is held to be sealed by the lower surface of the perimetric portion of the upper support member and the upper surface of the perimetric portion of the lower support member, so that a fuel channel through which a fuel gas flows is formed and defined in a space between the lower surface of a plane portion, which is positioned at the inner side of the perimetric portion of the upper support member, and the upper surface of the fuel electrode layer of the sheet body. Further, an air channel through which a gas (air) containing oxygen flows is formed and defined in a space between the upper surface of the plane portion, which is located at the inner side from the perimetric portion of the lower support member, and the lower surface of the air electrode layer of the sheet body.
In the structure described above, a fuel gas is supplied to the fuel channel and air is supplied to the air channel with the temperature of the SOFC being raised and heated to a working temperature (e.g., 800° C., hereinafter merely referred to as the “working temperature”) of the SOFC. Thus, the fuel gas and air are brought into contact with the upper surface and the lower surface of each of the sheet bodies respectively, whereby electricity generating reaction is produced for each sheet body.